package com.gssuren.demo.datasource.aop;

import com.gssuren.demo.datasource.annotaion.DataSource;
import com.gssuren.demo.datasource.config.DynamicContextHolder;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
 
/**
 * 动态数据源切面处理
 */
@Aspect
@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class DataSourceAspect {
    protected Logger logger = LoggerFactory.getLogger(getClass());
 
    @Pointcut("@annotation(com.gssuren.demo.datasource.annotaion.DataSource) " +
            "|| @within(com.gssuren.demo.datasource.annotaion.DataSource)")
    public void dataSourcePointCut() {
 
    }
 
    @Around("dataSourcePointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Class targetClass = point.getTarget().getClass();
        Method method = signature.getMethod();
 
        DataSource targetDataSource = (DataSource) targetClass.getAnnotation(DataSource.class);
        DataSource methodDataSource = method.getAnnotation(DataSource.class);
        if (targetDataSource != null || methodDataSource != null) {
            String value;
            if (methodDataSource != null) {
                value = methodDataSource.value();
            } else {
                value = targetDataSource.value();
            }
 
            DynamicContextHolder.push(value);
            logger.debug("set datasource is {}", value);
        }
 
        try {
            return point.proceed();
        } finally {
            DynamicContextHolder.clearDataSource();
            logger.debug("clean datasource");
        }
    }
}